In recent years, magnesium alloys have attracted much attention for their recyclability, low specific gravities, and good heat dissipation properties. Magnesium alloys can be substituted for plastic and steel material. For example, magnesium alloys can be used as casings for household electrical appliances, such as television receivers, notebook computers, and portable minidisk players.
Magnesium alloys are usually made into molded products using a die-casting method. Die-casting is a technique for manufacturing large quantities of casting with high precision and excellent surface texture by injecting molten metal into a precise mold at high pressure.
Generally, die-casting of magnesium alloy requires the use of a release agent to reduce the tendency of magnesium alloy product to become stuck to the mold. The release agent is usually sprayed on a molding surface of the mold. However, the release agent layer formed on the molding surface generally has a non-uniform thickness, which will cause errors in the resulting magnesium alloy products. Moreover, the release agent usually includes aliphatic hydrocarbon, carbonyl group (C═O), and silicone group (Si—O—C) compounds. These organic compositions can cause corrosion in the mold and further contaminate the resulting magnesium alloy products.
What is needed, therefore, is a die-casting mold core with excellent characteristics such as hardness, corrosion resistance, wear resistance, and ease of separation from the mold.